2 quick questions

[DRM500RUBYZR-1]

Originally Posted by spork2367

That simply isn't true. And the reference you posted is just some question answer page that any joe, dick or harry can respond to regardless of credentials or knowledge.

Mixing the two will have ZERO effect on corrosion in the system.

Dot 5.1 is also compatible with 3 and 4. Not Dot 5. Why did they number them like that? No clue.

3, 4, and 5.1 are all glycol based. 5 is silicon based and not compatible with any others.

Obviously mixing any higher number with a lower number negates a lot of the benefit as the effective boiling point is lowered an unknown amount. And a flush is always good every 10 years or so as the additive packages that prevent corrosion break down.

http://www.brakeandfrontend.com/brak...3-4-5-5-1-faq/

https://www.epicbleedsolutions.com/r...1-brake-fluid/

Who do I thank for the info, Tom, Dick or Harry, I think they all work for brake and front end or amsoil.
You (and they ) may certainly mix, feel free and have at it.


I will drain, flush, and fill, ESPECIALLY on someone else's car.


Maybe you are right.
But maybe you are not.
Why chance it over at most, an hour of labor and $10.00 of fluid.
Not a chance I take, so why would I recommend it to someone else?

[Corbusa]

Post # 666 ut oh

[Corbusa]

Just thinking ( scary huh?) , but if some are saying you can mix and others say No ( maybe they had problems ) Could it be maybe an issue b/t brands and not just the type? as for me I'll wait until I switch the master cyl etc ...

[32valvZ]

I never have mixed as a rule... just silly? maybe... just me... I suppose. As soon as I see my reservoirs getting dark, I use a turkey baster and change it with fresh fluid.... overkill? maybe... BUT, cheap to do and takes all of 5-10 minutes....

[spork2367]

Originally Posted by DRM500RUBYZR-1

Who do I thank for the info, Tom, Dick or Harry, I think they all work for brake and front end or amsoil.
You (and they ) may certainly mix, feel free and have at it.


I will drain, flush, and fill, ESPECIALLY on someone else's car.


Maybe you are right.
But maybe you are not.
Why chance it over at most, an hour of labor and $10.00 of fluid.
Not a chance I take, so why would I recommend it to someone else?

The website you linked is just some generic pass through website like quora. You have no idea where that info came from.

It's chemistry. I am right. It's not an opinion based argument. Some companies don't even distinguish between 3 and 4 on their bottles anymore. But I'm sure Valvoline doesn't have any decent chemists around...

And a complete flush is WAY more than an hour. How do you get the fluid out of the bottom of a caliper without removing the caliper and turning it upside down? So your removing all four calipers, disconnecting the hoses, turning them upside down...Just refilling and bleeding the system after you've drained it is going to take an hour.

How are you draining an ABS pump?

If all your doing is running 1-2 quarts of fresh brake fluid through, you are leaving 30% of the old fluid in the system.

Originally Posted by Corbusa

Just thinking ( scary huh?) , but if some are saying you can mix and others say No ( maybe they had problems ) Could it be maybe an issue b/t brands and not just the type? as for me I'll wait until I switch the master cyl etc ...

There are standards this is all made to. No secret ingredients that would interact with each other. The issue is misinformation gets spread across the web like wildfire.

Originally Posted by 32valvZ

I never have mixed as a rule... just silly? maybe... just me... I suppose. As soon as I see my reservoirs getting dark, I use a turkey baster and change it with fresh fluid.... overkill? maybe... BUT, cheap to do and takes all of 5-10 minutes....

So that reservoir constitutes maybe 50% of the system volume. And very little of that fluid is exchanged with what's in the rest of the system. You are just having a minor push/pull effect when you press and release the pedal. The purpose of the reservoir is just as an emergency storage system and to make up for minor expansion and contraction due to temperature changes. You could drain all but a 1/16th of an inch out of your reservoir and your brakes would continue to work just fine.


So while what you're doing may make you feel better, it has no real effect on the overall quality of the fluid in your brake system.

[DRM500RUBYZR-1]

Originally Posted by spork2367

The website you linked is just some generic pass through website like quora. You have no idea where that info came from.

It's chemistry. I am right. It's not an opinion based argument. Some companies don't even distinguish between 3 and 4 on their bottles anymore. But I'm sure Valvoline doesn't have any decent chemists around...

And a complete flush is WAY more than an hour. How do you get the fluid out of the bottom of a caliper without removing the caliper and turning it upside down? So your removing all four calipers, disconnecting the hoses, turning them upside down...Just refilling and bleeding the system after you've drained it is going to take an hour.

How are you draining an ABS pump?

If all your doing is running 1-2 quarts of fresh brake fluid through, you are leaving 30% of the old fluid in the system.



There are standards this is all made to. No secret ingredients that would interact with each other. The issue is misinformation gets spread across the web like wildfire.



So that reservoir constitutes maybe 50% of the system volume. And very little of that fluid is exchanged with what's in the rest of the system. You are just having a minor push/pull effect when you press and release the pedal. The purpose of the reservoir is just as an emergency storage system and to make up for minor expansion and contraction due to temperature changes. You could drain all but a 1/16th of an inch out of your reservoir and your brakes would continue to work just fine.


So while what you're doing may make you feel better, it has no real effect on the overall quality of the fluid in your brake system.

Again, thank you tom, dick,and harry.
You are an unimpeachable source, at least in your mind, but not to me.

As I said you do what makes you happy, although that seems quite the impossibility.

[spork2367]

Originally Posted by DRM500RUBYZR-1

Again, thank you tom, dick,and harry.
You are an unimpeachable source, at least in your mind, but not to me.

As I said you do what makes you happy, although that seems quite the impossibility.

I'm not the source, the manufacturers are. But I'm sure you're right and that every major brake fluid manufacturer is wrong or lying and that your totally anonymous source with no citation or known origin is correct.

It's not like anyone can look up a list of the ingredients in any brake fluid manufactured...oh wait, they can, it's called an SDS.

Again, this isn't about anyone's opinion, it's about the chemistry and what the manufacturers say based on that chemistry.

The only reason I've ever seen a manufacturer recommend against mixing is because putting a higher grade in with a lower grade negates the benefit buying the higher grade because you lose the advantage of the higher boiling point.